After being on the block for two years, the stumbling American Stock Exchange may have found a buyer – who’ll get it at just one-fifth of the asking price.

The Chicago-based private equity fund GTCR Golder Rauner LLC, is said to be ready to close the deal for about $100 million – far less than the original $500 million asked by NASD, the No. 3 exchange’s parent.

Sources say a second unidentified buyer is also seriously kicking tires for a deal.